Conventionally, there are known sample testing systems that include a transporting apparatus for transporting sample racks each capable of holding a plurality of samples (see, e.g., US Application Publication 2006/0216199).
US Application Publication 2006/0216199 discloses a sample testing system that includes: a transverse feeder (a transporting apparatus) for transversely feeding racks each holding a plurality of samples; engagement claws for feeding each rack to a transverse feed start position on the transverse feeder (i.e., to the end of the upstream side of the transverse feeder); and a blood analyzer for testing samples held in each rack that has been transversely fed by the transverse feeder. In this sample testing system, the transverse feeder sequentially and transversely feeds the racks from the transverse feed start position in a forward direction, thereby supplying the samples held in each rack to the analyzer in order of sequence in which the samples are held therein. Each time a sample is supplied to a sample supplying position that is located at a substantially central position on the transverse feeder, the analyzer obtains the sample from its rack to analyze the sample. When obtainment of sample by the analyzer is performed, the transverse feeder further transversely feeds the rack in the forward direction with respect to the sample supplying position so as to dispose the next sample held in the rack at the sample supplying position, thereby supplying the next sample to the analyzer. When the analysis proceeds in this manner, there is a case where the analyzer determines as a result of the analysis that retesting of a sample is necessary. In this case, since the sample needed to be retested, has already been fed transversely in the forward direction from the sample supplying position, it is necessary to transversely feed the rack in the reverse direction such that the sample needed to be retested is disposed at the sample supplying position again. In the sample testing system of US Application Publication 2006/0216199, in such a case, the rack is first transversely fed in the reverse direction to the transverse feed start position (i.e., to the end of the upstream side of the transverse feeder). Then, the rack is transversely fed in the forward direction again, whereby the sample needed to be retested is supplied to the analyzer (i.e., to the sample supplying position).
In the sample testing system described in US Application Publication 2006/0216199, when the rack is transversely fed in the reverse direction for retesting, the sample needed to be retested is once located at the sample supplying position during the transverse feeding. Nevertheless, the rack needs to be transported, passing through the sample supplying position, to the transverse feed start position. Further, the rack also needs to be transversely fed in the forward direction again from the transverse feed start position to the sample supplying position.